The process of creating several rolls of paper, such as newsprint, first involves creating a large “parent reel” of paper. The paper on this parent reel is then routed through a machine which slices the paper into varying widths and winds the sliced paper into rolls of varying diameter.
FIG. 1 illustrates aspects of the paper roll building process. The parent reel 1 is placed on a spool 2. The reel diameter 3 is a term of art, and refers to the distance between the edge of the spool and the outer edge of the reel. Paper from the reel 1 is fed through a machine 9 which slices the paper into the desired width and winds the paper into rolls 5 of varying set diameter 7.
Waste can occur in the process when the parent reel is either of insufficient diameter or excess diameter with respect to the diameter of the smaller rolls being built from the parent reel. The preferred method of paper roll manufacture is building parent reels to the exact size necessary to wind the needed sets of rolls, so that a minimum of parent reel building must take place. Unfortunately, this rarely happens, and the failure to do so results in waste of paper, materials, energy and labor. Often, extra paper is added to the parent reels to ensure that the roll diameter is not smaller than that ordered by the customer.
If the parent reel does not contain enough paper to make the rolls, the process must be halted while another parent reel is loaded, and the seam on a roll where the paper from the previous parent reel and the new parent reel meets must be mended.
Paper remaining on a parent reel after rolls are wound from it is called slab loss. This slab loss is excess and often ends up being discarded if the slab loss is of insufficient diameter to go through the winder without being topped-out or due to other reasons. A top-out is using paper from one parent reel and splicing it to a partially-built set from another parent reel. A top-out is necessary when the paper remaining on the parent reel is not long enough to build another set of rolls. Often, slab loss will increase after a succession of top-outs, as more paper is wound onto the parent reel than is necessary to build the rolls because the existing slab loss is not fully taken into consideration. When this occurs, the paper being loaded onto the parent reel must be cut back; specifically, the parent reel's optimal diameter must be reduced, so as to fully utilize all paper on the reel and eliminate the accumulating slab loss.
Waste also occurs when the parent reel contains cull paper in the midst of the parent reel. Cull paper is paper that cannot be used in the rolls because it does not match the required specifications. The winding process will sometimes cease prior to the cull paper being wound into the rolls, the cull paper must be removed or wound onto another set. The winding process must then begin again, after which there is a high probability of slab loss due to human error in calculating the proper size for the parent reel when taking the cull paper into consideration.
There are occasions when combinations of the above scenarios occur, such as building a top-out for a parent reel from which cull paper must be removed, or combining smaller reels into one parent reel for which a top-out is needed. In these situations, operator error and miscalculations are even more prevalent, resulting in waste.
The conventional methods of paper manufacture do not address the above problems. Responsibility for the requisite complicated mathematical computations and problem-solving falls to workers who may be inadequately trained, or whom are simply overwhelmed with the speed of the manufacturing process and the precision required to minimize waste in an environment with numerous workers, heavy materials and dangerous, fast-moving machinery.
There is a need for a new method of dealing with the aforementioned difficulties which allows for precise, immediate calculations of the parent reel size needed for a particular job, along with the ability to calculate slab loss, top-outs, the location of defects in a reel, and similar tasks. This method must be flexible enough to perform all the aforementioned calculations yet restrictive enough so as to minimize mistakes due to operator error.